Polyurethane foams have found wide and varied uses in industry. For example, the utility of flexible and semiflexible foams in cushioning and furniture construction and the great advantage of rigid foams in construction and insulation are now well-known. However, the range of utility of these foams has been somewhat limited by their flammability. Numerous attempts have, consequently, been made to impart flame retardance to these materials.
Polyurethane compositions containing various flame retardant additives are widely known. Most of these compositions contain non-reactive additives, that do not chemically combine with other constituents of the macromolecular chain. More recently there have appeared a number of reactive constituents, that chemically combine to form part of the polyurethane framework in the flame retardant foam. In most cases, the reactive additive constitutes the polyol or polyester component of the system that ultimately forms the polyurethane macromolecular network.
Halogenated polyether polyols have been used as flame retardants in polyurethane foams. For example, U.S. Pat. Nos. 3,741,921, 3,244,754 and 3,269,961 disclose the use of an adduct of 4,4,4-trichloro-1,2-epoxybutane and selected polyhydric alcohols in the preparation of flame-retardant polyurethane foams. While the aforementioned polyethers do impart a degree of flame retardance to polyurethanes prepared therefrom, the problem of flammability in foams has not been eliminated by the use of these adducts.
U.S. Pat. Nos. 3,324,108 and 3,300,474 disclose the reaction of epichlorohydrin with dextrose and sucrose, respectively. U.S. Pat. No. 3,402,169 discloses polyhalogenated polyethers that are said to be useful in the preparation of flame retardant polyurethane foam, which polyethers are prepared by reacting a polyhalogenated alkylene oxide with any one of a variety of polyhydric initiators having two to eight hydroxy groups.
Addition products of 4,4,4-trichloro-1,2-epoxybutane with certain amines have also been reported. Thus, Canadian Pat. No. 527,462 reports the reaction of 4,4,4-trichloro-1,2-epoxybutane with ammonia, diethylamine and p-chloroaniline without disclosing any particular utility for these products. U.S. Pat. No. 3,325,476 discloses the reaction products of 4,4,4-trichloro-1,2-epoxybutane with a large excess of primary or secondary amines to give hydroxyolefin amines. These compounds are said to be useful as pesticides or as catalysts for the isocyanate-alcohol reaction to produce polyurethane coatings, castings or foams. They may also serve as intermediates in the preparation of unsaturated monomers.